Retaining-wedge for dynamo-electric machines.



' R. B. WILLIAMSON.

RETAINlNG WEDGE FOR DYNAMO ELECTRIC MACHINES. APPLlcATxoN man BEC. 1. 191m 1,279,810. l Patented sept. 24,1918.

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UNITED sTATEs PATENTOFFICE;

ROBERT E. WILLIAMSON, OE MILWAUKEE, WISCONSIN, ASSIGNOE. 'ro ALLIs-OIIALMERS MANUFACTURING COMPANY, OE MILWAUKEE, WISCONSIN, A CORPORATION OF DELAWARE.

BETAINING-WEDGE FOR DYNAMO-ELECTRIC MACHINES. l

Application iled December 1, 1916. Serial N O. 135,081.

To all whom t may concern: y

Be it known that I, ROBERT B.y WILLIAM- soN, a citizen OI' the vUnited States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in Retaining-Wedges for Dynamo-Electric Machines, of which the following is -a speciication.

This invention relates in general to dynamo-electric machinery, and has particular reference 'to devicesfor securing windings in core slots of ksuch machinery. In dynamo-electric machinery of the distributed winding type wherein the winding elements are disposed in core slots, it is Often desirable that the slots be at least of the partially closed type. This provision is especially desirable in large size alternating current machines, especially in the armatures of turbo-generators, where the slots are necessarily wide on account of the large size ofthe conductors used and where it is de- Sirablethat thewindingsbe separated a considerable distance from the rotor in Order to keep A,down excessive currentvon short circuit,- and enerally where it is desirable that such win ings have considerable reactance; and itis also desirable in this latter lclass of machines that the devices for retaining these *windings in position in the slots be of such a character that eddy current losses are reduced toa minimum, and, likewise that they Vmay be. readily inserted Vinto and removed from `operative position with little danger of injury to the insulation of the winding elements in the slots.

, Y It is an object of this invention to provide animprovement in the construction of dynamo-electric machines wherein the windingsare disposed in slots, embodying animproved construction of a retaining wedge Or `These and .other Objects are attained by y ;.-thisinvention, the various novel features of which will 'appear from the description and drawings, disclosing embodiments of such Specication Of Letters Patent.

. air-gap.

Patented sept. 24, 191s.

invention, and will be out` inthe claims. n

In the accompanying drawings:

Figure 1 is a broken sectional kview of a laminated l.core with the windings retained in slots thereinby means of retaining wedges embodying features of this invention. ,'Fig. 2 isa plan view of the retaining wedge of F ig. 1. f

As illustrated in Fig. 1, a corelO, which maybe the stationary armature of a tur-bo-y generator, is provided with slots 12 for the reception of an armature winding 13, in the form of two superposed layers of suitably insulated conductors. The teeth 14 formed .between adjacent slots are recessed or undercut, as indicated at 15, to form retaining walls for wedges 1Gl vwhich secure the windings in position in the Slots.y

'Ihese securing or retaining wedges 16 are made up of a plurality of lannnations 17 of a cross-sectional shape such that,`when disposed in planes parallel to the laminations of the core, these wedge laminations t easily within the Open portion of the slots, that is, the portion between `the winding 13 and the The laminations are recessed or hollowed atthe -center and are ycut through at kthe air-gap side torremove the required `amount of material to provide for the proper reactance of the windings in the slots, the recess or hollow dividing each lamination into two side portions 18, 19 which approach eachother adjacent theair-gap side of the wedge, gradually tapering in cross-sectional area as they approach. At the lower side of the wedge, that is, the side opposite the airgap side, the side pieces of the lamination are of decreasing cross-sectional area, .the minimum vcross-sectional,area being at the middle of this lower side, as indicated at.

21, and this area being such that the side pieces may be readily sprung or distorted Y into intimate contact with the undercut sides yof the adjacent teeth to secure and lock the wedge in position. The laminations are assembled on a plurality'of rods 23 which are preferably riveted over at the ends, as indicated at 24, to secure and maintain the laminations in the form of a -unitary and `,readily handled retaining Wedge.

particularly pointed c The inner sides of the side walls or portions 18, 19 of the wedge 16 are recessed or cut away at 25, 26 respectively, to provide seats for a spreading or locking wedge or keyl 27'which is adapted to be driven between these side walls to force the saine laterally about the point 21 at the middle of the lower side as a pivot. A

lVhen the windings 13 are inserted npositioii in the slots 12, the open end ofeach slot adjacent the air-gap is preferably lined with insulating material 28 and the assembled retaining wedge 16 is slipped' into position from the end of the core part 14, the wedge being of such size as to be readily insertible in the open end of the slot without any damageto the insulation or windings by the edges of the laininations of which the wedge is composed. The locking or spreading wedgevor key 27 is then inserted with its spreading or wedge edges fitted in the recesses or seats 25, 26, in the side walls 1S,

19,- respectively` of the `wedge and is forced or driven into position, the width `of the body portion of 'this' key being slightly greater than the distance between the seats 25, 2G when the sidewalls are in normal position, to spread the side walls and force the same into intimate contact with the undercut sides of the adjacent teeth 1l, or the insulation 28, to firmly secure the retaining wedge inv position. A

The locking or spreading wedge or key 27 may be of metal, Vof magnetic or nonmagnetic material, or may be of insulating material, as desired, but the portions thereof that engage with the edges of the laminations of the main wedge and the windings `or insulation thereabout are preferably comparatively smooth aiid of fairly soft material so that the keycan readily accommodate itself to i'oughiiess of the coacting surface of the retaining wedge.

It will be apparent that, in accordance with this invention, there is provided adesirable type of wedge of such a character as -to contribute to the most eiiicient operation of the machine and such as may be readily inserted to operative'position in the slots of t-he machine, and secured therein and readily removed therefrom with comparatively little or no danger of damage to the windings or insulation in the slots.

1t should be understood that it is not desired that the invention, as claimed, be liiii ited to the exact details of construction vshown and described` for obvious modifications will occur to a person skilled in the art. It is claimed and desired to. secure by Letters Patent:

Y 1. 1n a dynaiiio-electric machine` the combination with a magnetizable core provided i with Vwinding-containiiig slots,- retaining wedges disposed in the open ends ofV1 said slots, eacliof said :retaining wedges being made up V.of a plurality of' laminations arranged transversely of the length of the slots and secured together, said laminations being liollowed or recessed andopen 'atthe air-gap side, 'the 'oppositeside' of said wedge being of decreased cross-section at the middle of said side, and a locking or spreading wedge or key seated in n'recesses iii the side portions of the retaining wedge and operativev to ydistort said side portions about the part of reduced cross-section and to force said side portions into operative position relative to the adjacent teeth. p

f 2. A retaining wedge for securing a wind- `ing iii the slots of a dynamo-electricmachine comprising a plurality of laniinations arranged `transversely of the length of the wedge and secured together, the laiiiiiiatioiis of said wedgeVbeing interiorly recessed'to provide spaced side walls separated at one endv and recessed at their inner sides` said laniinations being `of decreased cross-section adjacent the middle of theside oppositelthe air-gap side, and a spreading or locking rwedge orkey adaptedto seat in therecesses in said side walls and to distort said side tion for the purpose' of forcing said wedge -to operative position. v

3. Iii-a dynamo-electric machine, in coinbiiiatioii with a magnetic core'provided with `windiiig-coiitaining slots, retaining wedges disposed in the open ends of said'slots, `each of said retaining wedges being Vmade up of 1a plurality of laminatioiis arrangedV transversely ofthe length of the slots and secured together, saidlamina-tions being hollowed or recessed and open at the iair-gap side, the

opposite side of said wedge being of kdecreased crossesectionat the middle of said side, and a lockingor spreading wedgeI or key seated in recesses inthe side portionsof the retaining wedge leaving an opening at the air-gap side and operative to distort said side portions about tliepart ofgr'educed crossorkey adapted to seatin the recesses-in said side walls leaving airopeiiing at the air-gap side and to distort said sidewalls about, the part of reduced cross-section -for .thepurpose of forcing said wed'ge\to' -operative position.

5. Ina dynaino-electric inachine,in comwalls about the point of reduced cross-secbination with a magnetic core provided with air-gap,

and a spreading or locking Wedge or Winding-containing slots, retainin Wedges, lkey adapted to seat in the recesses in said disposed in the open ends of said s ots, each of said retaining Wedges being made up of a plurality of laminations arranged transversely of the length of the slots and secured together, said laminations being hollowed kor recessed and open at the air-gap side, the opposite side of said Wedge being of decreased cross-section at the middle of said side, and a locking or spreading wedge or key seated in recesses in the side portions of the retaining Wedge of a Width greater than the opening at the airgap side of said laminations and operative to distort said side portlons about the point of reduced cross-section and to force said side portions into operative position relative to the adjacent teeth.

6. A retaining Wedge for securing a Winding in the slots of a dynamo-electric machine comprising a plurality of laminations arranged transversely of the length of the Wedge and secured together, the laminatlons of said Wedge being interiorly recessed to provide spaced side Walls separated at one end and recessed at their inner sides, said laminations being of decreased cross-section adjacent the middle of the side opposite the Copies of this patent may be obtained tor ve cents Wuhinlt interior of said recess,

side Walls of a Width greater than the opening of the air-gap side of said laminations and to distort said side Walls about the part of reduced cross-section for the purpose of forcing said Wedge to operative position.

7. A retaining Wedge for securing a Winding in the slots of a dynamo-electric Inachine, said Wedge being interiorly recessed to provide spaced side walls separated a substantially greater distance at their inner sides than at the air-gap side and having recesses at their inner sides and a spreading or locking Wedge or key adapted to seat in the recesses in said side Walls and to distort said side Walls for the purpose of forcing said Wedge to operative position.

8. A Winding-retaining Wedge of dove tail form-for dynamo-electric machines, having a longitudinal recess open at the air gap side, said opening being of less Width than the and a Wedge or key for forcing the Walls of apart. p

In testimony whereof, the signature of the inventor is afiixed hereto.' f

ROBERT B. WILLIAMSON.

each, by addressing the Commiuioner `ot Patenti, on, D. 0."

the dove tail Wedge e 

